Abstract : An experiment that tests a novel method for deflecting molecular beams using inhomogeneous resonance fields is described. If an electric field rotates at the same frequency as a molecule placed in it, the field and molecule remain aligned and the dipole moment-electric field interaction does not average to zero. If the field is spatially inhomogeneous then there is a net force on the molecule. This force can be used in making a molecular beam deflector. Resonance deflection of molecules in the J = 0 and 1 rotational states of a molecular beam of CsF has been observed. The deflection is produced by passing a collimated molecular beam of CsF through the center of a TE(111) microwave cavity which is oscillating at the J = 0 1 transition frequency, 11.019 GHz. The theory of the effect as well as potential applications are also discussed. (Modified author abstract)